Table 2.

Cochlear implant use and speech perception scores at baseline, 18-, 36-, and 54-month follow-up.

					p-Values
	Baseline	18 mths	36 mths	54 mths	Baseline vs. 18 mths	18 vs. 36 mths	36 vs. 54 mths
CI usage (hrs/day)
n		54	36	21
Mean		12.1	12.8	12.4		0.045	0.554
Median		12.8	13.5	13.1
S.D.		2.9	2.9	3.5
Min		3.3	1.5	0
Max		17	19.8	17
CI usage (% of a 14 h day)
>90%		51.9	72.2	61.9
60–90%		37	19.4	33.3
30–60%		9.3	5.6	0
<30%		1.9	2.8	4.8
CVC Words (% correct)
n	95	51	32	23
Mean	42.83	70.71	73.75	78.13	0.000	0.306	0.264
Median	40	74	78	80
S.D.	26.2	21.2	16.2	14.8
Min	0	22	34	24
Max	94	98	94	96
CVC Phonemes (% correct)
n	95	51	32	23
Mean	65.85	85.41	86.8	91.01	0.000	0.540	0.121
Median	67	90	92	92
S.D.	21.8	13	12.3	8.7
Min	0.1	51	38	55
Max	97	99	97	98
SRT
n	87	51	32	22
Mean	10.94	5.05	4.31	3.66	0.000	0.111	0.328
Median	9.5	4.6	3.9	3.6
S.D.	7.2	3.4	2.8	2.3
Min	−0.9	−0.6	−1.1	−1.1
Max	21	15	11	9.3

Bold denotes significant differences (p < 0.05; significant at the 5% confidence level). CI use was measured using objective data logging information. Greater CVC Word and Phoneme scores show improved performance in quiet listening conditions. The SRT score measures the signal-to-noise ratio at which 50% of key words are correct in noise; therefore, decreases in SRT scores represent improved performance.